I'm pretty sure that's just "administrative" and imposed by the syntax (e.g. think Java/C++ function declaration syntax), instead of being something the compiler can't infer. Thanks for clearing this up, though.

It was a design decision, yes. We could infer them if we wanted to, but we don't.

    let rec factorial n = 
        if n = 0 || n = 1 then 1 
        else n * factorial (n - 1)

F#

Haskell:

  factorial n =
    if n < 2 
      then 1
      else n * factorial (n - 1)

I think the OCaml version will look almost exactly like the F# one.